这些日子，3991去哪了？从卫星地图上可以看到，3991离开天津后向西北飞行，3天后，定位信号稳定 停留于河北张家口市康保县的康巴诺尔湖附近。"那里是一处遗鸥的重要繁殖地，信号波动稳定，说明 3991有可能已经找到伴侣，停留在那里繁殖了。"杨亮亮说。 2024年，天津市规划和自然资源局联合杨亮亮所在的科研团队，共同开展天津市越冬遗鸥种群及其迁徙 规律研究。一年多来，共为40只遗鸥佩戴了背负式卫星追踪器。 这是今年4月5日发生的一幕，被放飞的3991曾是一只掉队的遗鸥。 遗鸥是国家一级保护鸟类，也是世界自然保护联盟确定的易危级物种。天津沿海滩涂湿地是遗鸥的重要 越冬地，每年春季迁徙前，大量越冬遗鸥会在此聚集。 3991是今年3月13日被天津市的护飞小队发现的。当时，它蜷缩在天津大神堂海滩的滩涂上，左翼和脚 爪受了很严重的伤。 "如果再晚半小时发现它，就很难救治了。"中国林业科学研究院森林生态环境与自然保护研究所副研究 员杨亮亮回忆。 经过科研人员和护飞小队的精心救治，3991的伤渐渐痊愈，体力也慢慢恢复，满足了放飞条件。"放飞 时，我们给这只遗鸥戴上了卫星追踪器。"杨亮亮解释，卫星追踪器是一种背负式的太阳能装置 ...

Group 1 - The article highlights the annual migration of the Beijing Swift, which travels approximately 16,000 kilometers from southern Africa to Beijing, showcasing its remarkable endurance and resilience [2][12][20] - The Beijing Swift is recognized as a cultural and ecological symbol of the city, with increasing attention and protection efforts contributing to its significance [3][7][14] - The swifts typically nest in the hidden spaces of ancient architecture, particularly in places like the Summer Palace, which provides ideal conditions for their breeding [14][16][20] Group 2 - Bird banding has been an important method for studying the migration patterns and behaviors of the Beijing Swift since the 1990s, with advancements in tracking technology enhancing research accuracy [21][27][29] - The banding process involves capturing the birds, measuring their physical data, and attaching identification rings, which allows researchers to track population changes and individual lifespans [23][25] - Recent upgrades to tracking devices, including light-sensitive locators and satellite trackers, have improved the precision of migration data collection [27][29][31]